1. Field of the Invention
The present invention relates generally to optical disc players and, more particularly, is directed to a disc loading apparatus for use in an optical disc player and in which a skewed amount of an optical disc is detected and an optical pickup head is controlled by a tilt adjusting mechanism on the basis of the detected output so that an optical axis of the optical pickup head remains perpendicular to a record surface of the optical disc.
2. Description of the Prior Art
Japanese Utility Model Laid-Open Gazette No. 63-55240 describes a disc loading and chucking mechanism which is applied to most of the existing optical disc players. According to this previously-proposed disc loading and chucking mechanism, a disc tray on which an optical disc is held is horizontally withdrawn to the disc reproducing position and then, a movable chassis on which a disc table is supported is elevated, whereby the optical disc is chucked to the disc table.
Incidentally, various kinds of optical discs are now available on the market, for example, optical video disc (i.e., optical video disc (VD)), VD single (optical video disc of small diameter), compact disc (CD), CD single (compact disc of small diameter) and the like. The optical video disc (VD), in particular, is large in diameter and weighs much so that, when this optical video disc is chucked on the disc table, the outer peripheral portion thereof is unavoidably skewed downward by a very small amount due to its own weight. To solve this problem, it has been proposed that the optical disc player is provided with a so-called tilt adjusting mechanism by which an optical axis of an optical pickup head is properly inclined in accordance with the skewed amount of the optical disc so that the optical axis of the optical pickup head becomes perpendicular to a record surface of the optical disc (see Japanese Patent Laid-Open Gazette No. 63-261542).
In the prior-art optical disc player having the optical pickup head tilt adjusting mechanism, the disc loading and the disc chucking are performed by driving a first motor, and the tilt adjustment of the optical pickup head is performed by driving a second motor.
Further, in the chucking mechanism of the prior-art optical disc player, a movable chassis on which the disc table is supported is connected to a fixed or stationary chassis so that it can rotate with an inclination, thereby to move the disc table in the upper and/or lower direction.
The above-described optical disc player according to the prior art includes not only the motor for effecting the first disc loading and disc chucking but also the motor for effecting the second tilt adjustment of the optical pickup head. In other words, this optical disc player has a two-motor drive system and therefore it becomes expensive to manufacture.
Furthermore, in the prior-art chucking mechanism of the optical disc player, since the movable chassis is supported on the stationary chassis so that it can rotate with an inclination, a supporting point of the movable chassis must be placed at the position very distant from the chucking portion, which makes the mechanism large in size. For this reason, it is very difficult to keep a space large enough to provide therein other mechanism parts and circuit boards.